This paper provides the outcomes of the Common Oceans Seabird Bycatch Data Preparation Workshop held in early 2018. The Project Team and workshop attendees revised the objectives and approaches to achieve the project goal. The assessment will now focus exclusively on estimating total seabird bycatch, or N, (which is a fisheries performance metric) and the species- or population-level consequences thereof. Three distinct, but linked, approaches were agreed: i) A ratio-based estimate of N generated by the Project Team, using publicly available data or best estimates provided by each participating country; ii) geospatial estimates of N generated by participating countries with their own data, possibly using procedures being developed collaboratively with the Project Team; iii) a Spatially Explicit Fisheries Risk Assessment (SEFRA) conducted in collaboration between participating countries and Dragonfly Data Science consultants based in New Zealand. Further intersessional work is planned before the final workshop to assist countries with analyses, if requested. The scale of this evaluation effort will be limited to the Southern Hemisphere.